Ultrasound energy is commonly used for imaging of internal body structures. Endoscopes are used for visual inspection of internal organs of living bodies. Endoscopes and catheters incorporating ultrasound transducers are well known. The instruments typically include a flexible tube that extends between a control housing at the proximal end and a probe at its distal end. The probe is controlled by an operator, and illumination and viewing means are usually provided in the system.
When optical means are used to view the interior surfaces of the body cavities through which the endoscope passes, the operator receives information concerning only interior surface conditions. Ultrasonics provide subsurface imaging information of underlying structure and interior organs. Thus, it is desirable to have both optical viewing and ultrasonic information at a desired location within a patient's body.
However, many current ultrasound devices may require that other functions, for example, the viewing function, be compromised to accommodate the ultrasound function. The increased costs and the possibility of interfering with an existing instrument capability by the combination with ultrasound imaging are two factors that have tended to limit usage of instruments with ultrasound imaging capability. Nevertheless, instruments lacking ultrasonic capability have little relative value when compared to a similar instrument with ultrasound capability. Therefore, upgrading is desirable for many existing instruments now lacking ultrasound capability.
It would be advantageous to have an ultrasonic imaging capability even when the instrument is otherwise a non-electrical device. For example, conventional catheters and dilators would be good vehicles for the addition of ultrasound capability.
What is needed is a low cost device for adding ultrasound imaging capability to existing instruments now used, without imaging, to perform diagnostic functions within body cavities.